"In particular, this year we're seeing evidence that a lot of the real negative signs in the cod stocks that have been with us for 20 years are turning around," George Rose, director of the Centre for Fisheries Ecosystems Research at Memorial University in St. John's, told The Canadian Press.

Monday marked the 20th anniversary of Ottawa's decision to impose a moratorium on the 400-year-old cod fishery in response to drastic declines in population off Newfoundland's north and east coasts, largely because of overfishing, mismanagement and environmental changes.

A ban that was supposed to last two years stretched into two decades, gutting the fishing industry.

A CBC News retrospective on the moratorium noted that in the mid-1980s, Canadian fishermen were hauling in 266,000 tonnes of cod annually, while foreign trawlers were taking close to 100,000 tonnes, despite a quota for foreign boats of only 36,000 tonnes.

Under the moratorium, the annual catch is less than two tonnes through an inshore recreational fishing quota.

A resource once so abundant that experts said overfishing was impossible was driven close to extinction.

But Rose said the lengthy ban finally appears to be paying off.

"We're seeing that the fish are living beyond five or six years of age," said Rose, part of a team that earlier this month completed a six-week voyage aboard the research vessel Celtic Explorer.

Ocean temperatures off the coast of Labrador were up to two degrees C higher than normal in some places, he said.

Officials of Fisheries and Oceans Canada, which took much of the criticism for mismanaging the cod fishery, said its scientists are aware of the research but taking a cautious approach.

Northern cod stock remains 90 per cent below levels measured in the 1980, Don Power, the department's head of groundfish research in St. John's, told The Canadian Press.

"There's a poor prognosis for the stock and recovery," said Power. "We're still a good ways down into this critical zone."

But it's another story on the West Coast, where a study suggests a serious long-term decline in sockeye salmon stocks, The Canadian Press reported.

The study, published Tuesday in the Canadian Journal of Fisheries and Aquatic Sciences, found "rapid and consistent decreases" in sockeye salmon productivity in stocks between Puget Sound in Washington state up along the B.C. coast to Alaska's Yakutat Peninsula.

Rivers and streams along the coast have been producing dramatically fewer adults, the study found.

Co-author Randall Peterman of Simon Fraser University said that since sockeye salmon are adaptable, these declining numbers suggest something may be going wrong with the ecological system.

"People who rely on salmon for their livelihoods, or their First Nations food and social and ceremonial purposes, really find sockeye populations very valuable, and so it's important to keep them going at a productive level," Peterman told The Canadian Press.

"Furthermore, there are very strong and important concerns about the long-term viability of many sockeye populations as well as other salmon populations, other species."

The study was produced for the recent Cohen Commission inquiry that looked into 2009 collapse of the Fraser River sockeye run.

Peterman said some have argued habitat degradation and pollution on a regional level have affected sockeye productivity. That's unlikely, he said, because populations in both pristine and heavily disturbed areas show similar downward trends.

More research is needed to try to discover the source of the decline and arrive at a response if possible, he said.